Abstract: A process is provided for purification of biogas to produce biomethane. The biogas is treated in a pressure swing adsorption unit to remove carbon dioxide and water. Other impurities including oxygen, hydrogen and carbon monoxide may be removed by an additional adsorption bed. The adsorption beds may be single stage or two-stage VPSA or PSA adsorption beds.

Abstract: A batch process for producing a purified, pressurized liquid carbon dioxide stream, includes withdrawing a liquid carbon dioxide stream (A) from a liquid carbon dioxide supply (10); introducing the liquid carbon dioxide stream (A) into a distillation column (B) having packing (C) therein, and stripping volatile impurities from the liquid carbon dioxide stream with the packing; vaporizing the liquid carbon dioxide stream (A) in a sump (D) of the distillation column (B) for providing a carbon dioxide vapor; withdrawing from a vaporized portion (F) of carbon dioxide vapor in the sump (D) a first vapor stream (G) vented from the distillation column (B); withdrawing from the vaporized portion (F) of the carbon dioxide vapor in the sump (D) a second vapor portion (H) vented from the sump into a conduit (I); and introducing the second vapor portion (H) in the conduit (I) into a carbon dioxide vapor feed stream.

Abstract: A combined plant for cryogenic separation and liquefaction of methane and carbon dioxide in a biogas stream, including a mixing means, a compressor, a first exchanger, a distillation column, a second exchanger, a separating means, an expanding means, and a separator vessel. Wherein, the mixing means is configured such that the recycle gas is the overhead vapour stream, and the first exchanger and the expanding means are combined.

Abstract: A combined plant for cryogenic separation and liquefaction of methane and carbon dioxide in a biogas stream, including a mixing means, a compressor, a first exchanger, a distillation column, a second exchanger, a separating means, an expanding means, and a separator vessel. Wherein, the mixing means is configured such that the recycle gas is the overhead vapour stream, and the first exchanger and the expanding means are combined.

Abstract: A system and method for remote monitoring and control of landfill and recycling operations provide an intelligent centralized platform for remote, real-time industrial data gathering and process control for management of landfill and recycling operations such as leachate, gas, water and other liquids. The system and method can directly upload machine data (such as liquid volumes, flows, level, equipment runtime, sorter data, status, etc) into a centralized platform. This data can be used for analytics and automation of processes and equipment control.

Abstract: A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO2 from a liquid NG process stream and processing the CO2 to provide a CO2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

Abstract: A process for the recovery of carbon dioxide from a gas mixture that includes pretreating a gas mixture comprising carbon dioxide, water vapor, and one or more light gases in a pretreating system to form a cooled gas mixture, fractionating the cooled gas mixture to recover a bottoms fraction comprising carbon dioxide and an overheads fraction comprising carbon dioxide and the light gases, passing the overheads fraction over a membrane selective to carbon dioxide to separate a carbon dioxide permeate from a residue gas comprising the light gases, recycling the carbon dioxide permeate to the pretreating system, and recovering at least a portion of the bottoms fraction as a purified carbon dioxide product stream is described.

Abstract: Gases are vented from a waste site such as a landfill, and the gases are separated into at least three streams comprising a hydrocarbon stream, a carbon dioxide stream, and residue stream. At least a portion of the carbon dioxide stream and hydrocarbon stream are liquefied or converted to a supercritical liquid. At least some of the carbon dioxide gas stream (as a liquid or supercritical fluid) is used in a cleaning step, preferably a polymer cleaning step, and more preferably a polymer cleaning step in a polymer recycling process, and most preferably in a polymer cleaning step in a polymer recycling system where the cleaning is performed on-site at the waste site.

Abstract: Gases are vented from a waste site such as a landfill, and the gases are separated into at least three streams comprising a hydrocarbon stream, a carbon dioxide stream, and residue stream. At least a portion of the carbon dioxide stream and hydrocarbon stream are liquefied or converted to a supercritical liquid. At least some of the carbon dioxide gas stream (as a liquid or supercritical fluid) is used in a cleaning step, preferably a polymer cleaning step, and more preferably a polymer cleaning step in a polymer recycling process, and most preferably in a polymer cleaning step in a polymer recycling system where the cleaning is performed on-site at the waste site.

Abstract: A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges including the steps of subjecting the inlet stream to fractional distillation providing a bottom product stream and a distillation overhead stream, passing the distillation overhead stream to a membrane unit producing a CO2 by-product stream and a hydrocarbon stream and chilling the hydrocarbon stream to produce a reflux liquid stream and a hydrocarbon gas product.

Abstract: A method of separating CO2 from a hydrocarbon gas inlet stream that is within predetermined pressure and temperature ranges, including the steps of subjecting the inlet stream to fractional distillation providing a CO2 bottom product stream and a distillation overhead stream, passing the distillation overhead stream to the inlet of a primary reflux drum producing a primary reflux liquid stream and a hydrocarbon vapor stream, subjecting the hydrocarbon vapor stream to membrane separation to provide a hydrocarbon product stream and a permeate stream, compressing the permeate stream and recycling the compressed permeate stream to the inlet of the primary reflux drum thereby providing a CO2 liquid product and a hydrocarbon gas product.

Abstract: An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.

Abstract: Gases are vented from a waste site such as a landfill, and the gases are separated into at least three streams comprising a hydrocarbon stream, a carbon dioxide stream, and residue stream. At least a portion of the carbon dioxide stream and hydrocarbon stream are liquefied or converted to a supercritical liquid. At least some of the carbon dioxide gas stream (as a liquid or supercritical fluid) is used in a cleaning step, preferably a polymer cleaning step, and more preferably a polymer cleaning step in a polymer recycling process, and most preferably in a polymer cleaning step in a polymer recycling system where the cleaning is performed on-site at the waste site.

Abstract: An ethane recovery process resulting in a reduction in the amount of carbon dioxide in the recovered NGL stream is provided. To reduce the amount of carbon dioxide, a fractionation tower is provided with a bottom reboiler, and possibly one or more side reboilers higher up in the tower that are integrated with the cooling train. The process disclosed modifies the flow of cold liquid from the separator and tower reboiling to reject some of the more volatile components such as carbon dioxide from the less volatile fraction while maintaining recovery of desirable components such as C2+ hydrocarbon components. The modification includes heating a part of the separator liquid and introducing it at least one stage below the remaining liquid.

Abstract: Process for pretreating a natural gas under pressure containing hydrocarbons, acid compounds such as hydrogen sulfide and carbon dioxide, and water. The natural gas is cooled to condense part of the water. The partially dehydrated natural gas is then contacted with a liquid stream consisting of a majority of hydrogen in two successive contact zones so as to obtain a natural gas containing substantially no water any more. Finally, this dehydrated natural gas is cooled to condense and separate the acid compounds, this cooling stage being carried out by means of a heat exchanger, an expander or a venturi neck.

Abstract: A plant for producing liquefied natural gas comprises a carbon dioxide recovery apparatus for natural gas absorbing and removing carbon dioxide from natural gas, a liquefying apparatus having a steam turbine, for liquefying the natural gas from which carbon dioxide has been removed by the carbon dioxide recovery apparatus, a boiler equipment for supplying steam to the steam turbine of the liquefying apparatus, and a carbon dioxide recovery apparatus for combustion exhaust gas including an absorption tower for absorbing carbon dioxide from combustion exhaust gas exhausted from the boiler equipment by absorbing liquid, and a regeneration tower for separating and recovering carbon dioxide from the absorbing liquid.

Abstract: A gas processiing plant has a de-ethaniizer (106) and a rctluxed absorber (103), wherein the absorber (103) operates at higher pressure than the de-ethanizer (106), and wherein at least a portion of the absorber bottoms product (7) is expanded to provide cooling for the absorber reflux stream and/or the distillation column feed stream. Especially contemplated gas processing plants include propane and ethane recovery plants, and where the gas processing plant is an ethane recovery plant, it is contemplated that the ethane product comprises no more than 500 ppm carbon dioxide.

Abstract: An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.

Abstract: For the separation of acid, carbon dioxide and/or hydrogen sulfide from a gaseous mixture comprising at least one lighter gas, e.g. methane, the gaseous mixture (1) is precooled at least once during a heat exchange operation E2; the resultant precooled gas mixture, flowing upwardly is cooled and rectified simultaneously in an approximately vertical heat exchange zone (ER) forming a downwardly-flowing countercurrent liquid reflux; the resultant rectified gaseous fraction (8) depleted in acid gases and enriched in light gas is collected at the top of the vertical exchange zone; and (d) a liquid fraction (4) enriched in acid gas components is collected at the bottom of the exchange zone. The collected liquid fraction (4) can be expanded and evaporated to provide cooling. The system has particular application for the treatment of natural gas or in petroleum refining or recovery operations.

Abstract: Carbon Dioxide is separated from other gases using autorefrigeration. In general, a feed gas containing Carbon Dioxide is compressed (100), and then expanded (250) to produce work. Carbon Dioxide in the feed gas is liquefied, and the liquefied Carbon Dioxide is then separated (282) from other components that remain gaseous. While all commercially viable embodiments are contemplated, embodiments are preferred in which the claimed methods and apparatus provide significant commercial advantages over the prior art. For example, it is preferred that feed gases are employed in which the Carbon Dioxide concentration is at least 40%, more preferably at least 60%, and still more preferably at least 80%. All percentages herein are given in mole percent. It is also preferred that feed gases be compressed to at least 15 bar absolute in all applications, at least 30 bar absolute in some embodiments, and at least 60 bar absolute in other embodiments.

Abstract: A process for producing carbon dioxide from a gas stream containing same pretreats the incoming raw gas to remove contaminants and particularly to protect degradation of the membranes utilized for separation. The temperatures of the various gas streams are carefully controlled to reduce water from the stream. By-product and other gas streams of the process are recycled in order to increase efficiency by utilizing the heating or cooling properties of the streams. In addition, streams containing minor portions of carbon dioxide are returned to the system for recovery.

Abstract: A distillation system for producing carbon dioxide, particularly from a feed which contains significant levels of light components, wherein the feed is at least partially condensed upstream of the distillation by indirect heat exchange with a multicomponent heat exchange fluid recirculating in a closed refrigeration loop, and/or the overhead from the distillation is condensed for reflux by indirect heat exchange with a multicomponent heat exchange fluid recirculating in a closed refrigeration loop.

Abstract: Process for treating a gas comprising one or more constituents to be separated, wherein the gas to be processed (G) is mixed at least partly with a solvent S selected to selectively retain at least part of the gas constituents to be separated, the mixture of gas (G) and of solvent (S) is cooled by circulating in at least one heat exchange zone so as to obtain, at the outlet of said heat exchange zone, at least a gas phase (G.sub.1) depleted in at least one of the constituents to be separated and a solvent phase (S.sub.1) enriched in said constituents, said enriched solvent phase (S.sub.1) is separated from said gas phase (G.sub.1) and it is recycled to the heat exchange zone in order to cool said gas-solvent mixture (stage b), said solvent phase (S.sub.1) consisting, at the outlet of the heat exchange zone, of at least a gas phase (G.sub.2) enriched in the constituents to be separated and of a liquid solvent phase (S), the gas phase (G.sub.

Abstract: A method is provided for removing carbon dioxide, ethane and heavier components from high pressure natural gas (10) comprises: partly condensing and expanding the high pressure natural gas (10) to obtain a gaseous stream (30) enriched in methane and carbon dioxide and two liquid streams (37 and 40) enriched in ethane and heavier components which are introduced into fractionation column (35); removing from fractionation column (35) fluid stream (45), heating (46) the fluid stream to obtain a reboiling stream (47) which is introduced into the fractionation column (35); removing from fractionation column (35) liquid stream (50) enriched in carbon dioxide, ethane and heavier components; removing from the top of fractionation column (35) a gaseous overhead stream (55) enriched in methane; cooling (56) the gaseous overhead stream (55) to obtain a two-phase fluid, separating (58) the two-phase fluid into cooled gaseous overhead stream (60) and first reflux stream (62) which is introduced into the fractionation colum

Abstract: This invention relates to a process for producing pressurized liquid rich in methane from a multi-component feed stream containing methane and a freezable component having a relative volatility less than that of methane. The multi-component feed stream is introduced into a separation system having a freezing section operating at a pressure above about 1,380 kPa (200 psia) and under solids forming conditions for the freezable component and a distillation section positioned below the freezing section. The separation system produces a vapor stream rich in methane and a liquid stream rich in the freezable component. At least a portion of the vapor stream is cooled to produce a liquefied stream rich in methane having a temperature above about -112.degree. C. (-170.degree. F.) and a pressure sufficient for the liquid product to be at or below its bubble point. A first portion of the liquefied stream is returned to the separation system to provide refrigeration to the separation system.

Abstract: A process for concentrating and recovering methane and carbon dioxide from landfill gas includes absorption of commonly occurring pollutants using a reduced amount of carbon dioxide absorbent which itself may be an in situ derived and recoverable constituent. Separated methane may be concentrated into a high heating value fuel, and a highly pure food-grade carbon dioxide product may also be recovered. Process streams may be used to provide fuel for compression and refrigeration and/or to regenerate carbon dioxide absorbent.

Abstract: A process with few parts is provided to remove carbon dioxide from a feed stream. The solid forming property of carbon dioxide and the low vapor phase solubility of carbon dioxide at cold temperatures form the basis for the separation process. The cooled feed stream enters a separation vessel where process means are provided to produce and separate carbon dioxide solids. Carbon dioxide is removed from the vessel as a carbon dioxide rich liquid stream. Purified cold vapor is removed from the separation vessel as a product stream.

Abstract: The invention relates to a method to reduce flue gas in incineration processes that are carried out with an oxidizing incineration gas consisting of a flue gas that is returned to the circulation system and of a technically produced oxygen. A stoichiometrically-related proportion of the flue gas that is not added to the incineration gas has a CO.sub.2 fraction greater than 70%. In order to reduce the flue gas, the fraction of flue gas that is returned and not used as incineration gas in the incineration process is removed from the circulation system and liquefied in the device.

Abstract: Waste landfill gases are treated and separated by a combination of gas cleaning, gas compression, gas cooling, and gas absorption processes to produce high quality liquefied natural gas, liquefied carbon dioxide and compressed natural gas products.